as counterpart to _set_current_name. Here's why:
_set_current_name is used to set a name proposal. When there's a format selector (combo box for example) as extra widget, I want to change the proposed name with the extension matching the newly selected format. E.g. user typed "test.png" and changes the format to "GIF", I want to update the 'typed' filename to "test.gif".
I could do that by getting the current file/uri, finding the filename part, convert to UTF-8, change + _set_current_name (that's what gimp does, see the rather complicated gimp_file_dialog_proc_changed function in 
http://cvs.gnome.org/viewcvs/*checkout*/gimp/app/widgets/gimpfiledialog.c?rev=1.55 ) but I want a simpler way. Also _get_current_name would eliminate problems by not converting the user input first to locale encoding then back.